1. Field of the Invention
This invention relates to wheat flour milling apparatus and processes and especially to equipment and procedure for producing white flour from wheat grain which is much simpler, less costly and more efficient than previously available milling apparatus and methods.
2. Description of the Prior Art
In order to produce white flour from wheat, it is necessary that the bran outer layer be substantially removed from the internal endosperm and germ portions of the wheat grains, and that the endosperm fraction then be ground into a flour of relatively uniform constituency and particle size. The make-up of the white flour as well as its fineness and uniformity of particle size are important factors in obtaining quality products containing the flour.
Typical commercial flour mills employ a gradual reduction system of milling. Even relatively small milling units usually employ many grinding, sifting and purification passages. As many as 50 pairs of rollers may be used in comminuting the wheat grains and separating the particulate product into requisite fractions of product fineness and freedom from bran and the like, along with as many as 25 classification stations. At the very least, large commercial mills have heretofore used at least 13 separate grinds with intermediate sifting. Typically, in mills that process hard winter wheat, conditioning times of from 12 to 20 hours were common.
This means that a large capital outlay is required to build such a mill and therefore is normally more cost efficient to construct mills capable of producing large amounts of finished flour, rather than to build smaller plants in closer proximity to the producing fields themselves. Furthermore, trained personnel are required throughout the plant because of the complicated nature of the typical gradual reduction milling process. The processing apparatus is of sufficient complexity that highly trained personnel are required to operate the facility and to maintain the equipment.
As a result of the high installation and operating costs for these large mills, circumstances arise where the milling plants are located adjacent satisfactory labor markets, transportation facilities and requisite sources of utilities even though the distance between such a plant and the fields where the wheat is grown are necessarily relatively far apart.
There are circumstances though where a highly refined flour product does not meet all market needs and therefore is not saleable in a particular demographic or geographic area. For example, in many underdeveloped countries, high extraction flours (approximately 80%) are more desirable and it is very difficult for countries in this category to negotiate the purchase and construction of large mills and trained personnel or oftentimes not available to operate the plants. In addition, there are a great number of entrepreneurs in the United States who find it commercially attractive to produce their own white flour for home baking, restaurant use and similar purposes. At the present time, the only small mills available in the United States are for production of whole wheat flour exclusively.